Liberty was rated 5,000 lbs and 24 ft long for both the diesel and 3.7 L gasser.
In any case, the rig you spotted was crazy. Every time I see one like that I say a little prayer nobody gets killed and the idiot driving learns a lesson. I suspect the latter is a futile request.
Last one I saw looked like somebody moving on a budget. U-Haul trailer behind an SUV. The rear seat and back end of the SUV was crammed full, roof rack piled high, and trailer also. It was obvious the rear suspension was bottomed out on the stops so that the tail pipe was barely off the ground and the bolt below the hitch ball was getting sanded every time he drove over a white line between lanes. Front end looked light to me, but surely that wasn't why he was having trouble going around curves.